Crossover Study of Propranolol vs Ivabradine in POTS
Status:
Recruiting
Trial end date:
2025-12-31
Target enrollment:
Participant gender:
Summary
1.0 BACKGROUND Postural tachycardia syndrome (POTS) is a disorder of chronic orthostatic
intolerance characterized by symptoms of palpitations, lightheadedness, chest discomfort,
shortness of breath, blurred vision, and mental clouding. These symptoms occur during
standing and are associated with a marked increase in heart rate (HR) in the absence of
hypotension, which typically resolve when sitting or lying down. Most importantly, POTS is
associated with a very poor quality of life and significant functional disability. POTS
patients commonly experience mental clouding ("brain fog") even while lying down or seated,
which poses significant limitations to daily activities .
Unfortunately, there is a relative paucity in the literature assessing therapies for POTS
patients. Given that excessive tachycardia on standing is a fundamental component of this
syndrome, a handful of studies have evaluated medications that reduce HR. Ivabradine is newer
drug that is a selective If channel blocker that reduces HR without affecting other
cardiovascular functions.
2.0 RATIONALE / STUDY PURPOSE The investigators propose to compare the efficacy of
propranolol and ivabradine on HR response to standing, and symptom burden in patients with
POTS.
3.0 Study Design This will be a single-center double-blind placebo-controlled randomized
crossover trial conducted in patients with POTS to compare effects of (1) oral ivabradine 5
mg bid plus placebo BID (to fill out a QID schedule); (2) oral propranolol 20 mg qid; and (3)
oral placebo qid in POTS patients. After a baseline screening assessment following a washout
period of 7 days, participants will be randomized to start with a 4-week course of either
ivabradine, propranolol or placebo. The other two treatments will be given in separate 4-week
courses with a 7-day washout period between phases, with each participant acting as his or
her own control. At the end of each 4-week phase, participants will complete the
symptom-rating and HRQOL questionnaires, and also undergo tilt table testing to assess the
change in HR at 10 min with head up tilt.
Participants will undergo POTS testing at baseline and at the end of each 4-week treatment
course. This will involve a total of 4 separate study visits.